Tester for blast-cavities.



PATENTED DBG. l, 1903.

o. B. LANHAM. TESTER POR BLAST GAVITIBS.

APPLICATION FILED AUG. 2i. 1902.

N0 MODEL.

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- UNITED STATES Patented December 1, 1903.

PATENT OFFICE.

TESTER FOR BLAST-CAVITIES.

SPEG'LFIGATION formingpart of Letters Patent No. 745,357, dated December 1, 1903. Application tiled ugust 2l, 1902. Serial No. 120.568. (No model.)

To all whom t may concern:

Beit known that I, OALBREITH B. LANHAM, a citizen of the United States, residing at Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Testers for Blast-Cavities, of which the following is a specification.

My invention relates to testers for blastcavities, the object of the same being to ascertain the size of the blast-cavity made by the cartridge at the bottom of the drilled hole preparatory to inserting the powder in the same for the purpose of blasting.

In thedrawings forminga part of this specication, and in which like symbols of reference represent corresponding parts in the several views, Figure l is a vertical sectional view of the drilled hole, showing the device in its operative position in the same. Fig. 2 is a vertical sectional view of the device, showing the various parts of the same. Fig. 3 is a view of the dial used in connection with the device, and Fig. 4 is a view of a portion of the measuring-chain.

l represents the drilled hole; 2, the tubeof the tester, in which the various parts of the device operate; 3, a hinged elbow orvjoint pivotally connected with the bottom of the tube, and 3a alpin forming the hinge between the tube and elbow, the same having a shoulder 4 to prevent t-he elbow from opening further than at right angles to the tube.

5 is a graduated rod working within the tube formed within the main tube 2, said rod having a pivotal connection with a huttjoint measuring-chain 7.

8 is a link connecting the elbow 3 with a rod 9, the object of the same being to control said elbow and when desired draw it within` a recess l0, formed in the tube or casing 2.

ll and 12 are handholds for the rods 5 and 9 for operating the same.

13 isa dial, and 14 a pointer adapted to be placed on the tube 2 above the dial to indicate the position of the same. The dial is marked with concentric circles representing inches from one to six, which for convenience are intended to indicate feet.

16 is a space on ldial to keep a record of depth ofv hole and the various changes of depths made by different springings.

The tube 2, which is designed to afford protection to the parts, is preferably formed in sections of about four feet in length, so as to be detachable, and thus adapted for various depths of holesjexcept the lower part 15, which is made six feet to conform to the measuring-chain 7, which is also six feet, it being unnecessary to ever have the device any shorter. The other parts-such as the rods, ze-are also made in sections to agree with the tube. The chain 7 is bend-able only in one direction and is what might be called a rule or butt-chain-that is, it has butt-joints, the object of the same being to v,make it feed regularly in-the direction ofthe elbow 3. The rod 5 has the usual'scale of inches and feet upon its edge, so as to show instantly how far the chain reachedl within the excavation.

' The operation of the device is as follows:

Thehole having been drilled in the ground.

and the preliminary cartridge having been exploded to enlarge the bottom of the'same, the dial is first placed at the top of the hole or tube and secured by spikes or the like connected with the same and the tube with its elbow closed inserted in the hole. The rod 5 is then manipulated to operate the chain 7. When the extent ofthe excavation in one direction is ascertained, the tube is turned in another, and so on until theentire size of the excavation is ascertained. As the rod is withdrawn the measurementis of course ascertained and marked on the dial, and so on until all the various measurements have been made, and the sum total can then easily be adduced. The dial is also marked N S E W, so that with the aid of the pointer 14 the exact location of the various soundings may be known.

Of course any manner of marking on the dial may be used so long as it is on the line which would indicate the proper number of feet measured.

Having now fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In a tester for blast-cavities, a main protecting-casing, a measuring-chain adapted to operate within the same, means for operating the chain, and means for directing the chain.

2. In a tester for blast-cavities, a main casing, a measuring-chain, means for operating the chain, and an elbow connected to the bottom of the casing to direct the chain.

3. In a device of the character described, the combination with the main casing, of a measuring device adapted to operate in the same, an elbow hinged to the bottom of the casing, a rod to control the elbow, and a link connecting;r the free end of the elbow with the rod.

4. In a device of the character described, a main protecting-casing, and a butt-joint measuring-chain adapted to operate in the same, the butt-joints permittingbending only in one direction.

5. In a tester for blast-cavities, the combination with the measuring device, of a dial npon which to record the soundings and a pointer working in conjunction with the dial. G. In a device of the character described, the combination with the main casing formed with a cnt-away portion at its base, ot' e measuring device adapted to operate in the same, an elbow connected to the main casing and adapted to be received within the cut-away portion ofthe casing, means for operating the elbow, and a partition within the main casing forming separate compartments for the measuring device and elbow-operating means. In testimony whereof I affix my signature in presence of two witnesses.

CALBREITH B. LANHAM. Witnesses:

STUART E. OBERLIN, A. J'oHNs. 

